U.S. patent number 8,047,263 [Application Number 11/722,438] was granted by the patent office on 2011-11-01 for device for the horizontal continuous strip casting of steel.
This patent grant is currently assigned to Salzgitter Flachstahl GmbH. Invention is credited to Guido Bormann, Hellfried Eichholz, Markus Schaperkotter, Karl-Heinz Spitzer.
United States Patent |
8,047,263 |
Spitzer , et al. |
November 1, 2011 |
Device for the horizontal continuous strip casting of steel
Abstract
The invention relates to a device for the horizontal continuous
strip casting of steel, especially steel with high manganese
content, for producing a pre-strip with a thickness .ltoreq.15 mm.
The device includes a tundish containing the melt, a primary
cooling zone having two deflection pulleys and a revolving cooled
conveyor belt, and a secondary cooling zone which follows the
primary cooling zone and has a housed roller table. A guide element
having at least one roller is hereby arranged at the end of the
primary cooling zone and before the start of the secondary cooling
zone.
Inventors: |
Spitzer; Karl-Heinz
(Clausthal-Zellerfeld, DE), Eichholz; Hellfried
(Ilsede, DE), Schaperkotter; Markus (Braunschweig,
DE), Bormann; Guido (Ilsenburg, DE) |
Assignee: |
Salzgitter Flachstahl GmbH
(Salzgitter, DE)
|
Family
ID: |
36130152 |
Appl.
No.: |
11/722,438 |
Filed: |
December 15, 2005 |
PCT
Filed: |
December 15, 2005 |
PCT No.: |
PCT/DE2005/002277 |
371(c)(1),(2),(4) Date: |
June 21, 2007 |
PCT
Pub. No.: |
WO2006/066552 |
PCT
Pub. Date: |
June 29, 2006 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100000703 A1 |
Jan 7, 2010 |
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Foreign Application Priority Data
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Dec 21, 2004 [DE] |
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10 2004 062 636 |
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Current U.S.
Class: |
164/442;
164/490 |
Current CPC
Class: |
B22D
11/0631 (20130101); B22D 11/1284 (20130101); B22D
11/143 (20130101) |
Current International
Class: |
B22D
11/12 (20060101); B22D 11/10 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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39 90 711 |
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Mar 1993 |
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DE |
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0 707 908 |
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Apr 1996 |
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EP |
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60 187448 |
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Sep 1985 |
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JP |
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01 313157 |
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Dec 1989 |
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JP |
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WO 00/59650 |
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Oct 2000 |
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WO |
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Other References
Steel research 74 (2003), No. 11/12, pp. 724-731 Direct Strip
Casting (DSC)--an Option for the Production of New Steel Grades,
Karl-Heinz Spitzer et al. cited by other.
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Primary Examiner: Ward; Jessica L
Assistant Examiner: Ha; Steven
Attorney, Agent or Firm: Feiereisen; Henry M. Day; Ursula
B.
Claims
What is claimed is:
1. A device for the horizontal continuous casting of steel,
comprising: a tundish containing melt; a primary cooling zone
placed adjacent the tundish for receiving the melt and producing a
pre-strip with a thickness of <15 mm, said primary cooling zone
having two deflection pulleys and a revolving cooled conveyor belt
looped about the deflection pulleys; a secondary cooling zone
downstream of an end of the primary cooling zone; and a guide
assembly having rollers in spaced-apart offset relationship along
an upward track and rollers along a following further track at the
end of the primary cooling zone and before a start of the secondary
cooling zone to neutralize an expansion of a bottom side of the
pre-strip, wherein the rollers of the upward and further tracks are
located above and below the pre-strip such that in a transport
direction of the pre-strip along the upward track a first roller
below the pre-strip is positioned offset to the right of a first
roller located above the pre-strip and to the left of a second
roller located above the pre-strip, and wherein the rollers above
and below the pre-strip in the further track are not arranged in
offset relationship.
2. The device of claim 1, wherein the steel has a manganese
content.
3. The device of claim 1, wherein the secondary cooling zone has a
housed roller table.
4. The device of claim 1, wherein the further track is a horizontal
transport path.
5. The device of claim 4, wherein the rollers are positionally
adjustable in relation to the pre-strip.
6. The device of claim 1, wherein a first group of the rollers is
arranged in offset relationship with respect to a transport
direction of the conveyor belt and with respect to a casting
line.
7. The device of claim 1, wherein a first one of the rollers in
transport direction is located directly above a trailing one of the
deflection pulleys.
Description
The invention relates to a device for the horizontal continuous
strip casting of steel, in particular of steel with high manganese
content, for producing a pre-strip with a thickness of .ltoreq.15
mm according to the preamble of claim 1.
Horizontal continuous strip casting plants for producing a
pre-strip of steel, in particular of steel with high manganese
content, are known (steel research 74 (2003), No. 11/12, pp.
724-731).
The known device includes a tundish containing the melt, a primary
cooling zone having two deflection pulleys and a revolving cooled
conveyor belt, and a secondary cooling zone which follows the
primary cooling zone and has a housed roller table.
In this device, the conveyor belt, which is filled with water from
below, has a length which is sized to effect a full solidification
of the pre-strip at the end of the primary cooling zone so that the
pre-strip can be easily further processed (dividing, rolling,
coiling).
During solidification on the revolving conveyor belt, the cooling
conditions (top side, bottom side) are asymmetric, with the upper
half of the cast pre-strip being warmer than the lower one. After
leaving the conveyor belt, the bottom side of the pre-strip is
reheated from the top side. This heat flux from top to bottom
causes the bottom side of the pre-strip to expand, resulting in an
upwardly directed arching of the strip edges (called U
configuration), after the pre-strip leaves the conveyor belt.
The described profiled shape of the pre-strip upon leaving the
conveyor belt is unwanted because, on one hand, it can have
backlash up to the conveyor belt, i.e. the pre-strip bears no
longer flat on the conveyor belt, and, on the other hand, the
further transport and threading is impeded for all downstream
aggregates.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a device for the
horizontal continuous strip casting of steel, in particular of
steel with high manganese content, for producing a pre-strip with a
thickness of .ltoreq.15 mm, by which the unwanted profiling of the
pre-strip is reduced and in a best case scenario even entirely
prevented.
This object is attained by a device for the horizontal continuous
casting of steel, in particular of steel with high manganese
content, for producing a pre-strip with a thickness of <15 mm,
which device includes a tundish containing melt, a primary cooling
zone having two deflection pulleys and a revolving cooled conveyor
belt, a secondary cooling zone which follows the primary cooling
zone and has a housed roller table, and a guide element having at
least one roller which is arranged at the end of the primary
cooling zone and before the start of the secondary cooling
zone.
According to the teaching of the invention, a guide element having
at least one roller is arranged at the end of the primary cooling
zone and before the start of the secondary cooling zone. The guide
element normally includes several rollers located above and below
the pre-strip and arranged either in `top-to-top` formation or in
offset relationship.
The individual rollers either rest upon the pre-strip being
conducted, or they have a distance thereto and can be positionally
adjusted in order to randomly change the distance to the
pre-strip.
The guide properties can be advantageously enhanced by an
arrangement in which the bottom rollers are leveled with the
casting line and the top rollers are arranged in the form of a
wedge. The wedge may have a continuous or segmental
configuration.
The trapezoidal shape represents a particular configuration of the
segmentation. This means that the first top rollers bear closely on
the pre-strip after the pre-strip leaves the conveyor belt, whereas
the subsequent ones have a distance, and the last rollers, before
the start of the secondary cooling zone, bear again closely on the
pre-strip
This trapezoidal shape is preferably selected to prevent the
backlash of the profiling of the pre-strip into the casting region
and to ensure the threading into the downstream aggregates.
Moreover, the pre-strip is thus exposed to smallest possible forces
in the area of decreased ductility.
An alternative arrangement for the guide element is characterized
by a guided upward movement of the pre-strip which is subsequently
conducted in a plane above the casting line. As a result of the
upward movement, the expansion of the bottom side of the cast strip
is neutralized.
Also the known roller arrangement in straightening machines can be
exploited for this purpose. The guide element includes hereby a
line of rollers in offset relationship, whereby either the top or
bottom rollers that are spaced to the pre-strip dip between the
respectively opposite rollers to a predefined extent so that the
pre-strip passes the set of rollers in a wavy manner.
BRIEF DESCRIPTION OF THE DRAWING
Further features, advantages, and details of the invention are set
forth in the following description with reference to several
exemplary embodiments shown in a drawing.
It is shown in:
FIG. 1 a first exemplary embodiment of a continuous strip casting
plant with a guide element according to the invention,
FIG. 2 a second exemplary embodiment,
FIG. 3 a third exemplary embodiment,
FIG. 4 a fourth exemplary embodiment,
FIG. 5 a fifth exemplary embodiment with wedged guidance,
FIG. 6 a sixth exemplary embodiment with trapezoidal guidance.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 is a longitudinal view of a first exemplary embodiment of a
continuous strip casting plant 1 with a guide element 2 according
to the invention. The continuous strip casting plant 1 includes a
revolving conveyor belt 3 and two deflection pulleys 4, 4'. Also
visible is a lateral seal 5.
Melt 7 transported by means of a ladle 6 towards the continuous
strip casting plant 1 flows via a bottom opening 8 into a tundish 9
which is constructed as an overflow tank. The melt is transferred
from the tundish 9 onto the upper strand of the conveyor belt 3 and
fairly quickly solidified as a result of the intense cooling by the
bottom side of the upper strand. The equipments required for
cooling as well as the housing of the continuous strip casting
plant with respective inert gas atmosphere have been omitted for
the sake of simplicity. The produced pre-strip 10 is substantially
solidified at the end of the conveyor belt 3.
This area of the continuous strip casting plant is also designated
as primary cooling zone. Before the secondary cooling zone,
comprised of a housed roller table (not shown here), follows, there
is arranged a guide element 2 therebetween in accordance with the
invention. The guide element 2 normally includes rollers 11, 11'
located above and below the pre-strip 10'. In the illustrated first
exemplary embodiment, the rollers 11, 11' are arranged in so-called
`top-to-top` formation and rest upon the pre-strip.
The following examples depict variations of this basic arrangement,
with same reference numerals being chosen for same parts.
FIG. 2 differs from FIG. 1 by the feature that the first of the top
rollers 11 is arranged in direct opposition to the rear deflection
pulley 4'.
FIG. 3 shows that the top rollers 11 are arranged in offset
relationship to the bottom rollers 11'. The individual rollers 11,
11' may hereby, as shown, bear upon the pre-strip 10', or, acting
like a straightening machine, the top or bottom rollers are spaced
to the pre-strip 10' and dip between the respectively two opposite
rollers 11, 11' to a predefined extent so that the pre-strip 10'
passes the set of rollers in a wavy manner.
For example, the rollers 11'' located underneath the pre-strip 10',
as shown in FIG. 3, would bear upon the pre-strip 10', while the
rollers 11 situated above at a distance to the pre-strip 10' would
be positioned lower so as to dip more or less deep between the two
rollers 11' respectively positioned opposite thereto.
FIG. 4 shows the possibility to neutralize the expansion of the
bottom side of the pre-strip 10' through provision of a guided
upward movement. The first rollers are hereby disposed offset in
transport direction and in relation to the casting line. The
further movement is horizontal again, preferably with the common
`top-to-top` formation of the rollers 11, 11'.
FIG. 5 shows a variant in which the bottom rollers 11' extend level
with the casting line, and the top rollers 11 form, as viewed in
transport direction, an opening wedge. The top rollers 11 must
hereby be adjustable in the direction of the pre-strip 10'. The
apparatuses required for that purpose have been omitted for the
sake of simplicity.
In contrast to FIG. 5, the top rollers 11 are arranged in FIG. 6 in
such a way as to define a trapezoidal shape. This means that the
first of the top rollers 11 bears upon the pre-strip 10', and the
following rollers 11 have a changing distance to the pre-strip 10',
whereas the last roller 11 again bears upon the pre-strip 10'.
All illustrated variants are intended to suppress or entirely
eliminate a U-shape of the pre-strip 10', when leaving the conveyor
belt 3.
* * * * *